Transcript document

Agenda
• Crash course on H323
• How is SIP different ?
• Problems in Interworking
• Possible Solutions
• Current Implementation/Status
• Q/A
• Demo
29-Mar-16
© 1999, Columbia University
Multimedia Communication Protocol
Terminal/
User Agent
Q931
H245
RTP
RAS
H450
Gatekeeper
(Guardian)
MCU
(Meeting Hall)
H323 Box
Gateway
(Bridge to another
network)
H323 Network
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© 1999, Columbia University
Terminal/
User Agent
Terminal Control/Devices
Codecs
Q931
H245
RAS RTCP
RTP
TPKT
TCP
UDP
IP and lower layers
H323 Stack
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A
IP Router
User Agent
IP Router
Guardian
Meeting Hall
User Agent
B
C
H323 On Internet,
Physical Configuration
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User Agent
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A
Guardian
User Agent
User Agent
Meeting Hall
User Agent
C
B
Logical Configuration
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•Take permission from your guardian
•Find the address of the person to call
•Dial the number/Pick up the phone
•Tell the other party what all languages you can speak/understand
•Wait for him to tell you his capabilities
•Tell him what language you are going to speak during the conversation
•Start talking (and listening)
•When you are done say Bye to other party
•Hang up
•Inform your guardian that you are done.
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•Take permission from your guardian ( RAS Admission Control)
•Find the address of the person to call ( RAS Address resolution)
•Dial the number (Q931 call setup)
•Tell the other party what all languages you can speak/understand
(H245 capability negotiation)
•Wait for him to tell you his capabilities (H245 Capability negotiation)
•Tell him what language you are going to speak during the conversation
(H245 Logical channel signaling; languages=codecs)
•Start talking (and listening) (Data transfer using RTP/RTCP)
•When you are done say Bye to other party (H245 end session)
•Hang up (Q931 call termination)
•Inform your guardian that you are done. (RAS Admission Control)
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Some additional things are also required.
•Search for your guardian (RAS Gatekeeper discovery)
•You can operate without a guardian
•You can use multiple languages to communication
•You can switch language during your talk as long as you talk what the
other guy understands, however you have to explicitly tell him that you
are switching.
•Saying Bye before hanging up is optional
And many more . . .
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+ It works
+ There are many existing implementation ... Some are free.
+ Supports lots of languages (codecs).
+ Interoperable with other other protocols H320 (ISDN),
H324 (POTS).
- Too complicated (a) ASN (b) Huge
- Lots of protocols are combined together under the
heading H323 ... Redundancy.
- Guardian is overloaded and Meeting hall is full !!
- Firewalls ? ...Difficult to develop.
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Text based ... No legacy from ISDN/POTS
Mr. B, you are invited to talk to me. I can understand
English and German.
OK, But I can understand English and French only.
Let’s talk
Mr. A
Words... Mots... Words ... Words ...
Words... Words ... Wörter ... Words
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Mr. B
SIP/IP
H323/IP
Cellular
PSTN
ISDN
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SIP/IP
Gateway
H323/IP
Cellular
Gateway
Gateway
ISDN
PSTN
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• User Registration
• H245 <=> SDP
• Direct Data Traffic between SIP and H323
• Transparent Support for Codecs
• Call sequence mapping (next slide)
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H323 Network
SIP Network
Dial Mr X
Mr. B, you are invited to
talk to me. I can
understand
English and German.
Pickup...Connected
I speak/understand
English andFrench.
Mr. A
Mr. X
OK, But I can understand
English and French only.
I’ll speak English
Let’s talk
I’ll speak French
Words...
Words...
Words...
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Words...
© 1999, Columbia University
Mr. B
H323 Network
SIP Network
Dial Mr A
Mr. X
Pickup...Connected
Mr. A, you are invited to
talk to me. I can
understand
English and German.
I speak/understand English andFrench.
Mr. A
I understand English andGerman.
I’ll speak English
OK, But I can understand
English only.
I’ll speak English
Let’s talk
Words...
Words...
Words...
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Words...
© 1999, Columbia University
Mr. B
H323 Network
SIP Network
Dial Mr B
Pickup...Connected
Mr. B, you are invited to
talk to Mr A. He can
understand
English only.
I speak/understand
English (default).
Mr. A
Mr. B
Mr. X
I’ll speak English
OK, But I can understand
English and French only.
I’ll speak English
Let’s talk
Words...
Words...
Words...
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Words...
© 1999, Columbia University
H323 Network
SIP Network
Dial Mr B
Mr. B, you are invited to...English
OK, ... English and French only.
Pickup...Connected
I understand En and Fr.
Mr. A
Mr. B
Mr. X
I’ll speak English
I’ll speak English
Let’s talk
Words...
Words...
Words...
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Words...
© 1999, Columbia University
All these solutions have one or the other problem.
We Need Smart H323 Phone ...
Dial Mr B, Also I can speak English and can
Understand English and German
Pickup..Connected, OK...I understand English
and I’ll speak German.
H323 V2.0 Fast Connect
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© 1999, Columbia University
H323 Network
SIP Network
Mr. B, you are invited to talk to Mr A.
He speaks English and understands
English and French
Dial Mr B. Speak En
Understand En and Fr
Pickup...Connected
Speak English and understand
English.
OK, ... I understand English and
German.
Let’s talk. But Mr A
understands only English.
Mr. A
Mr. X
Words...
Words...
Words...
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Words...
© 1999, Columbia University
Mr. B
• Two way call. Either side can initiate the call
• Fast Connect as well as non-Fast connect
• RTP packets directly between the endpoints
• Codecs supported ?
• Multiple calls simultaneously - ?
• User Registration - NO
• Call transfer and Multiparty conference - NO
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Signaling GatewayApplication
API
API
H323 Library
SIP Library
H323 Cloud
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SIP Cloud
© 1999, Columbia University
H323 SIP
Signaling
Gateway
PC
PC
E-Phone
(Embedded SIP
user agent)
®
Windows
Netmeeting®
V3.0.1
LAN
Signaling Connection (Q931,H245,SIP,etc)
Data Connection (RTP/RTCP)
29-Mar-16
© 1999, Columbia University